When Are VMT Impacts From A Project Acceptable?
Since adopting its current guidance in 2020, Caltrans has addressed vehicle-miles traveled (VMT) as a negative environmental impact under the California Environmental Quality Act (CEQA) and its implementing regulations (“Guidelines”). In practice, this means analyzing, avoiding, and mitigating induced VMT that results from projects on the State Highway System.
Environmental analysis sometimes provides “bright-line” rules. For example, where resource agencies dictate policy regarding wetlands, a “no net reduction” in wetland area is generally acceptable. With respect to other resources analyzed under CEQA. lead agencies such as Caltrans have substantial discretion to determine the extent to which various public policies may warrant the approval of a project, notwithstanding the potential that the project may cause significant adverse impacts. (See for example Public Resources Code section 21081.) Induced travel falls into this latter category. Under Caltrans’ “Transportation Analysis Framework/Transportation Analysis under CEQA” (TAF/TAC) guidance documents that implement Public Resources Code section 21099, Caltrans must forecast the induced VMT attributable to its projects and demonstrate efforts to identify and implement mitigation measures. CEQA requires all “feasible” mitigation be applied. CEQA cites timing as well as “economic, environmental, social, and technological factors” as considerations in determining feasibility (Public Resources Code section 21061.1). Lead agencies, such as Caltrans, are left to determine what level of effort, allocation of resources or technical difficulty is required for something to be considered infeasible. Minimal efforts on mitigation may be subject to legal challenge, but in general, and assuming substantial evidence supports the conclusion, lead agencies have leeway to decide what is feasible in terms of mitigation. Part of the determination of feasibility for a particular mitigation measure may include the commitment of funding on an ongoing basis for a strategy that requires continuous operational support￼.
When a lead agency formally approves a project, whose substantial adverse impacts will not or cannot be fully mitigated, it must issue a Statement of Overriding Considerations (SOC) as part of the CEQA process. According to the Guidelines, “CEQA requires the decision-making agency to balance, as applicable, the economic, legal, social, technological, or other benefits, including region-wide or statewide environmental benefits, of a proposed project against its unavoidable environmental risks when determining whether to approve the project” (Title 14 Cal. Code Regs. §15093).
What follows is not intended as rigid guidance, but instead as insight into the process the Department will employ in making its decisions on whether a VMT-inducing project may proceed. Every project is unique and may trigger different considerations or different weighing of benefits and impacts than what is described here. The examples provided are hypothetical illustrations of how some types of projects might be viewed, based in part on these general considerations:
- Has the project development team (PDT) worked thoroughly to identify VMT-reducing or -neutral project alternatives, and provided a compelling reason for not selecting those alternatives?
- Has the PDT described its efforts to revise the preferred alternative to eliminate or minimize induced VMT?
- Has the PDT worked thoroughly to identify VMT-mitigation options including those regarding active transportation, transit, land use, lane management, and transportation demand management? In that effort, has the PDT meaningfully engaged partners and affected communities on anticipated VMT impacts and meaningful mitigation options?
- Has the PDT availed itself of feasible mitigation options, including those that require enforceable agreements with partners
- Has the PDT fully considered ongoing funding commitments that may be required to support operations of a particular mitigation measure over a sustained period? Is there an identified funding stream such as toll revenue that can be accessed?
- Has the PDT considered the organizational structure or entity that will be used to assure that ongoing VMT mitigation strategies are funded and carried out is in place (commitments from government agencies, Transportation Management Agencies, or other entities capable of making ongoing funding commitments)?
- Has the PDT documented the facts and rationale used when concluding mitigation options not included were deemed to be infeasible? (While mitigation may add substantial costs to a project, there is no firm upper limit on such costs. In order to demonstrate that a mitigation measure is infeasible due to cost, the PDT must show that it explored and exhausted all reasonable methods for funding the measure. Project-development delays are generally not sufficient reasons for considering a mitigation option infeasible.)
- Has the PDT shown that mobility benefits from the project will not be eroded by induced VMT attributable to the project?
If project teams can successfully address considerations such as those above, as they apply to the project, the Department will weigh whether the project’s benefits outweigh the negative VMT impacts. The Department may be able to be more definitive in this judgment over time, as projects are reviewed and the courts weigh in. For now, these are some hypothetical examples of potential reasons to move forward with a project with induced VMT that is not mitigated below a level of significance, with some additional specific considerations relevant to each:
- Roadway capacity changes necessary to reduce fatal and severe injury crashes. Project teams should demonstrate that operational or other non-VMT-generating options would not be effective and should also cite crash histories and locations or other specific data showing the need for the proposed safety improvement. Any crash modification factors (CMFs) or countermeasures cited should relate to effectiveness in reducing fatal and severe injuries. Safety measures should be consistent with a safe-systems approach. Any VMT increases are forecast would likely lead to safety degradation, e.g. at freeway ramps where added traffic from induced VMT poses hazards to active travelers and motorists on surface streets, raising the burden on the project to show a safety benefit.
- Projects that occur in low-congestion conditions and that 1) do not substantially affect travel times, now or in the future, or 2) do not serve as low-density development attractors. In these cases, even where lane-miles-based tools may suggest induced VMT, the context may argue that such effects will be less than significant. Any project that promises to create time-travel savings and attendant economic benefits, as calculated in the CalBC or similar tools, would not qualify for such consideration, by definition.
- Projects that may induce VMT at the project level but can be shown to have a greater downward effect as an element in a system or corridor. A new managed-lane segment may induce VMT, but if it allows for new system-level roadway pricing that provides funding for non-auto travel, it may have a net benefit for VMT. Note the future condition would need to be enforceable and demonstrably effective in lowering VMT, as not all managed-lane strategies would do so.
- Projects envisioned as part of a VMT-neutral corridor plan, even if the projects themselves do induce VMT. Again, the corridor plan would need to be enforceable. If the VMT-inducing project comes after the VMT-reducing elements of the corridor plan, a showing that both were conceived as a coherent plan or joint development would be needed. A lengthy time gap between the projects will make that showing more difficult.
- Projects providing for evacuation routes. Such projects would need to be consistent with one or more of the following: 1) an adopted emergency operations plan, 2) a local general plan safety element that has been updated and adopted pursuant to evacuation route information requirements in Government Code 65302(g)(5) and 65302.15 (see SB 99  and AB 747 , or 3) recommendations issued by the Board of Forestry and Fire Protection, in consultation with the State Fire Marshall and the local agency, to improve safety of a subdivision with more than 30 dwelling units lacking a secondary egress that is determined by the Board and the State Fire Marshall to be at significant risk, pursuant to Public Resources Code 4290.5. As stated in the list of considerations above, VMT-neutral solutions, such as reversible lanes or improved shoulders that could be used to provide equally effective and safe evacuations, must be shown to be infeasible.
- Projects that Caltrans believes have been mitigated to a level below significance, but where measurements are qualitative or imprecise or where indefinite ongoing mitigation funding is not assured. A Statement of Overriding Consideration, addressing any “significant and unavoidable” VMT resulting from the imprecision or uncertainty, could be appropriate.
The Department instituted a process in April 2022 for assessing State Highway System (SHS) roadway capacity increasing projects for risk of being unable to mitigate VMT impacts. This process involves reviews and concurrence steps between districts and headquarters in the Project Initiation and Project Approval/Environmental Document phases. The Caltrans director must sign off on any projects that do not mitigate VMT to below a level of significance before draft and final environmental documents are circulated. As with any capacity-increasing project, only after the environmental document is final can design and construction begin.
As noted, it is expected that project reviews and potential court rulings will cause Departmental best practices on unmitigated VMT to evolve. Changes or additions to the content of this hot topic will be noted on the SB 743 landing page.